If steel cables or steel belts serve as support means, the replacement state of wear is determined in that the number of wire breakages is counted or in that the support means is magnetically inductively monitored. However, this method is not suitable or is suitable only to a limited extent for aramide cables as support means.
A method of detecting the wear of the support cable of an elevator is known from the specification JP 11 035 246 A. The part of the support cable which slips on the drive pulley is exposed to the greatest wear. In addition, slipping of the support cable on the drive pulley has the effect that the journey time is extended. A correlation thus exists between the degree of wear and the journey time. This correlation is now used in the method for detection of the wear in order to make a conclusion about the degree of wear from the ascertained journey times.
Initially the car call signals are detected and the journey times needed by the car to go from the call floors to the destination floors are calculated therefrom. The calculated journey times are subsequently compared with wear values in order to ascertain that shaft section in which the car moves most frequently. The wear of the corresponding cable section is now investigated on the basis of this recognition.
However, this form of embodiment has the following disadvantage. Due to the fact that the journey time depends not only on slip, but also additionally on some other parameters such as, for example, the load in the car, only relatively imprecise conclusions about the prevailing slip can be made by detection of the journey time. If the journey time lengthens, this can have various causes. A stronger degree of slip is merely one of several possible causes.